A design method for the rear baffle of an impact-resistant mining dump truck

Abstract

The present invention provides a design method for the rear baffle of an impact-resistant mining dump truck. Through the arc surface design, the stress state of the rear baffle of the cargo box can be effectively improved, and the shear force and bending moment in the plate can be weakened to the greatest extent, so that the shear force on each section of the rear door approaches zero and the bending moment approaches zero, obtaining an excellent stress state, and effectively improving problems such as large deformation, local cracking and poor material sealing caused by the rear baffle bearing pressure and being impacted.

Description

Technical Field

[0001] The present invention relates to the technical field of mining dump trucks, and specifically to a design method for the rear baffle of an impact-resistant mining dump truck cargo box. Background Art

[0002] Mining dump trucks are key equipment in open-pit mine mining and large-scale earthwork construction, featuring large load capacity and high working efficiency. In their actual operating environment, they often face harsh and complex road conditions in mines. Under these complex road conditions, mining dump trucks have to undergo complex working conditions such as driving uphill and downhill fully loaded, driving on rough roads, sharp turns, braking, crossing obstacles and sinking, loading and unloading materials, etc. These factors cause the rear baffle door of the cargo box to bear complex and variable forces. In particular, during the unloading process, the rear baffle door of the cargo box is often impacted by irregular groups of falling stones from the upstream stacked materials, which makes the main part of the rear baffle door, the rear baffle, bear multiple and intensive impact loads from the groups of falling stones, resulting in convex and concave deformation of the rear baffle, continuous accumulation of plastic deformation and damage, causing weld cracking and tearing of the rear baffle base material, greatly shortening the service life of the rear baffle door of the cargo box and increasing the maintenance cost of the product.

[0003] The applicant has found in practice that there are at least the following problems in the prior art:

[0004] 1) The rear baffle door of the cargo box is severely deformed, resulting in poor material tightness and material leakage along the road.

[0005] 2) The structures of the rear baffle doors of the cargo box are highly homogenized and the force distribution is unreasonable. They are all welded structures of a single-piece flat rear baffle and stiffeners, and the only difference is the different stiffener layout schemes adopted for the rear baffle. There are slight differences in the morphology, number and position of the stiffeners. However, this structure of the rear baffle door disperses the impact external load to the central axis and cross-section of the rear baffle, generating additional shear forces and bending moments, increasing the overall structural load-bearing burden of the rear baffle door and being unfavorable for the realization of the long service life of the cargo box. Summary of the Invention

[0006] In order to solve the problems existing in the above prior art, the present invention provides a design method for the rear baffle of an impact-resistant mining dump truck cargo box, which can effectively improve the stress state of the rear baffle of the cargo box and weaken the shear force and bending moment in the plate to the greatest extent.

[0007] The technical solution adopted by the present invention: A design method for the rear baffle of an impact-resistant mining dump truck cargo box, comprising the following steps:

[0008] S1: Determine the boundary range of the rear baffle, with the height dimension defined as h and the width dimension defined as l; establish a coordinate axis, with the height direction of the rear baffle as the X-axis, the width direction as the Y-axis, and the normal direction as the Z-axis;

[0009] S2: Establish the cross-sectional outer contour curve with the maximum vector height in the width direction, and its analytical expression is:

[0010]

[0011] Among them, P max is the maximum pressure borne by the bottom of the rear baffle, and f is the maximum sagitta in the width direction of the rear baffle;

[0012] S3: Establish the outer contour curve of the cross-section with the maximum sagitta in the height direction, and its analytical expression is:

[0013]

[0014] S4: Based on the rear baffle boundary in step S1, the outer contour curve of the cross-section with the maximum sagitta in the width direction in step S2, and the outer contour curve of the cross-section with the maximum sagitta in the height direction in step S3, perform boundary blending to obtain the final rear baffle surface.

[0015] Preferably, in step S2, according to the magnitude of the friction coefficient, select the strong friction form solution or the weak friction form solution to determine the maximum pressure P max borne by the bottom of the rear baffle. The strong friction form solution is:

[0016]

[0017] The weak friction form solution is:

[0018]

[0019] In the formula, G represents the total weight of the loaded material, and μ represents the friction coefficient

[0020] Preferably, it further includes the step

[0021] S5: Set the plate thickness t, and thicken the neutral plane of the rear baffle surface in step S4 symmetrically on both sides.

[0022] It should be noted that for different boundary range dimensions h, l, the maximum sagitta f can be flexibly adjusted according to actual design requirements. According to the calculation methods of formula (1) and formula (4), the design requirements of the rear door that can meet the cross-section shear force tending to 0 and the bending moment tending to 0 can be obtained, and all fall within the protection scope of the present invention.

[0023] The beneficial effects of the present invention: It can effectively improve the stress state of the rear door of the cargo compartment. The internal forces on any cross-section of the rear door are only normal forces, and the shear force and bending moment both tend to zero. It can effectively improve the impact tolerance of the rear door of the cargo compartment to the irregular falling stone group of the upstream stacked materials, delay the accumulation process of plastic deformation and fatigue damage, reduce the probability of weld cracking and tearing of the rear baffle base material, extend its service life, and reduce the product maintenance cost. Brief Description of the Drawings

[0024] Figure 1 Schematic diagram of the outer contour curve of the cross-section with the maximum rise in the width direction;

[0025] Figure 2 Schematic diagram of the outer contour curve of the cross-section with the maximum rise in the height direction;

[0026] Figure 3 Schematic diagram of the hybrid modeling of the single-cluster curve boundary in the X direction of the neutral plane of the rear baffle;

[0027] Figure 4 Schematic diagram of the hybrid modeling of the single-cluster curve boundary in the Y direction of the neutral plane of the rear baffle;

[0028] Figure 5 Schematic diagram of the curved surface of the neutral plane of the rear door. Specific implementation manner

[0029] To further illustrate the technical details and advantages of the present invention, specific descriptions will be made below in combination with the accompanying drawings and embodiments.

[0030] A design method for the rear baffle of an impact-resistant mining dump truck, the rear baffle adopts an arc surface design, and the arc surface is gradually enveloped by two clusters of curves, including the following steps:

[0031] S1: Determine the boundary range of the rear baffle, set the height dimension as h and the width dimension as l; establish a coordinate axis, with the height direction of the rear baffle as the X axis, the width direction as the Y axis, and the normal direction as the Z axis;

[0032] S2: Establish the outer contour curve of the cross-section with the maximum rise in the width direction, and its analytical expression is:

[0033]

[0034] where P max is the maximum pressure borne by the bottom of the rear baffle, and f is the maximum rise in the width direction of the rear baffle; the outer contour curve of the cross-section with the maximum rise in the width direction is as Figure 1 shown.

[0035] According to the magnitude of the friction coefficient, select the strong friction form solution or the weak friction form solution, and determine the maximum pressure P max of the strong friction form solution as:

[0036]

[0037] The weak friction form solution is:

[0038]

[0039] By equating the expressions on the right side of equations (2) and (3), the critical value of the friction coefficient is obtained as 0.41. When the friction coefficient μ is greater than or equal to the critical value, the solution with strong frictional force is selected; otherwise, the solution with weak frictional force is selected.

[0040] S3: Establish the outer contour curve of the cross-section with the maximum sagittal height in the height direction, and its analytical expression is:

[0041]

[0042] The outer contour curve of the cross-section with the maximum sagittal height in the height direction is as Figure 2 shown.

[0043] S4: Based on the rear baffle boundary in step S1, the outer contour curve of the cross-section with the maximum sagittal height in the width direction in step S2, and the outer contour curve of the cross-section with the maximum sagittal height in the height direction in step S3, use proe software for boundary blending to obtain the final rear baffle surface, as Figure 5 shown.

[0044] In this embodiment, Figure 3 is obtained by boundary blending of a cluster of seven curves in the width direction of the rear door, and the curve numbers are 1 to 7 respectively; Figure 4 is obtained by boundary blending of another cluster of seven curves in the height direction of the rear door, and its curve numbers are 1 to 7 respectively.

[0045] S5: Set the plate thickness t, and thicken the neutral plane of the rear baffle surface in step S4 symmetrically on both sides.

[0046] It should be noted that for different boundary range dimensions h, l, the maximum sagittal height f can be flexibly adjusted according to actual design requirements. According to the calculation methods of equations (1) and (4), the design requirements of the rear door that satisfy the cross-section shear force tending to 0 and the bending moment tending to 0 can be obtained, and they all fall within the protection scope of the present invention.

Claims

1. A design method for the rear baffle of an impact-resistant mining dump truck carriage, characterized in that: It includes the following steps: S1: Determine the boundary range of the rear baffle, with the height dimension set as h and the width dimension set as l; establish a coordinate axis, with the height direction of the rear baffle as the X-axis, the width direction as the Y-axis, and the normal direction as the Z-axis; S2: Establish the outer contour curve of the section with the maximum camber in the width direction, and its analytical expression is: Among them, P max is the maximum pressure borne by the bottom of the rear baffle, and f is the maximum sagitta in the width direction of the rear baffle; S3: Establish the outer contour curve of the section with the maximum camber in the height direction, and its analytical expression is: S4: Based on the rear baffle boundary in step S1, the outer contour curve of the section with the maximum camber in the width direction in step S2, and the outer contour curve of the section with the maximum camber in the height direction in step S3, perform boundary blending to obtain the final rear baffle surface.

2. The design method for the rear baffle of an impact-resistant mining dump truck carriage according to claim 1, characterized in that: In the said step S2, according to the magnitude of the friction coefficient, a strong-friction-force form solution or a weak-friction-force form solution is selected to determine the maximum pressure P borne by the bottom of the rear baffle max The strong-friction-force form solution of The weak form solution of the frictional force is: In the formula, G represents the total weight of the loaded material, and μ represents the friction coefficient.

3. The design method for the rear baffle of an impact-resistant mining dump truck carriage according to claim 1, characterized in that: It further includes the step S5: Set the plate thickness t, and perform bilateral symmetric thickening on the neutral plane of the rear baffle surface in step S4.

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